PRE-FORMING DIE TO PREVENT SPRING BACK

摘要

A preforming die for preventing spring back is provided to bend a tube type blank workpiece considering the deformation of a product due to a spring back phenomenon, and reduce production time of the product and reduce the entire cycle time of the product accordingly by reducing the number of processes of bending the tube type blank workpiece in a preforming operation. A preforming die(100) for preventing spring back comprises: a base frame(10); a first die(20) which is installed on a top part of the base frame, and has a first bending face(21) formed on one side face thereof correspondingly to the bending shape of a tube to be formed; a spring back compensation unit(30) including a rotary shaft(31) installed at one side of the base frame such that the rotary shaft is joined with the first die to rotatably join the first die with the base frame, and a first supporting part(32) for fixing the position of the first die; a movable frame(40) installed on the top part of the base frame such that the movable frame is slidable by an actuator; and a second die(41) which is connected to the movable frame and supported by a second supporting part(53) such that the second die is pressurized toward the first die according to operation of the movable frame, and which has a second bending face(42) formed on one side face thereof correspondingly to the first bending face of the first die.